Sectional box structure



M. M. CLAYTON. SECTIONAL BOX STRUCTURE.

APPLICATION ILED JULY 16,1920- Patented Feb. 22; 1921.

wm/assEs UNITED STATES PATENT OFFICE.

MARTIN M. CLAYTON, OF BEAVER, PENNSYLVANIA, ASSIGNOR TO NATIONAL METAL MOLDING COMPANY, OF PITTSBURGH, PENNSYLVANIA, A CORPORATION OFPENN- SYLVANIA.

Specification of Letters Patent.

SECTIONAL BOX STRUCTURE.

Patented Feb. 22, 1921.

Application med J'uly 16, 1920. Serial a... 396,787.

To all whom it may 'concemr' Be it known that I, MARTIN M. CLAYTON, residing at Beaver, in the county of Beaver and State of Pennsylvania, a citizen of the United States,'have invented or discovered certain new and useful Improvements in Sectional Box Structures, of which improvements the following is a specification.

It is the object ofthe invention to produce a sectional metallic box structure which may be made up of as many units as may be desired. The units may easily be assembled and firmly secured together, and they may also be economically manufactured, and with a minimum wastage of metal.'

While the' invention is utilizable in box structures of many kinds and for many uses, it is of particular advantage in boxes used in the electric wiring of buildings, which are set in the wall to receivethe connections of the wires with switches, receptacles and the like, and are generally known as outlet boxes.

In the accompanyin drawings Figure 1 is a perspective view of an open-front outlet box of the usual type, embodying the present invention. Fig. 2 is a sectional view, taken through the securing devices. Fig. 3 is an end elevation. Fig. 4 is a fragmentaryview in section. l I

In this case the box structure is shown as made up of two open-front body sections A, B, each'having o posite side walls 1, 2,

and a back wall 3 o anysuitable form, in

which are shown the usual knockouts 4. The

opposite ends of the structure are closed by the plates 5.

In sectional box structures of this general type, made up of a plurality of body sect ons with theedges of ad acent sections butted against each other, various devices have been employed for securin' the sections together, usually involving t e, provision upon at least one edge of eachfsection of integral projecting lugs or ears, which are of suflicient length to overlap the body of an 1 adjacent section and be secured thereto by screws, when the edges of'the two sections are butted together. This necessitates in the making of each section the wastage of prac tically all of a strip of metal of a width equal to the length of these projecting lugs, and where these structures are produced on a large scale such wastage is in the aggreare forme gate a very considerable item of the total cost of manufacture.

it to overlap a corresponding reversely bent lug on the next abutting section suiiiciently to receive a screw for securing the lugs together. Thus the axis of the securing screw is made to intersect the vertical plane of the junction of the edges of two abutting sections, instead of the entire screw being located at one side of such vertical plane as heretofore. I

Referrin again to the. drawings, there on the opposite edges of the metallic strip which is to be bent up to-form oneof the body sections the integral projections 6, (but of materially less length than formerly), and slits 7 are cut in the body of the strip at each side of said projections, the holes to receive the securing screws, and to be presently described, being preferably cut out at the same time. The lugs 8 and 8' which are thus formed in the opposite edges of the strip are then bent in opposite directions, so as to lie in planes at an angle to the plane of the body of the strip. Thus, referring to Fig. 2, when the strips thus formed have been bent to form the body sections A and B, and the said body sections are butted together edge to edge, the outwardly bent lugs 8' on the inner edge of the wall 1 of section A will rest'flat upon the lnwardly bent lug 8 of the abutting inner edge of the wall 1 of section B, while on the other side of the box the outwardly bent, lug 8' on the ed e of section B will rest upon the inward y bent lug 8 on the edge of section A.

. The lugs 8, which are bent in the direction to project inwardly of the box structure, are provided each with a threaded opening 9 to receive the shank of a securing screw 10. Each of the outwardly bent lugs receive the head of the securing screw when the latter is tightened up. Thus the securing screws 10 may be seated in the inwardly bent lugs 8 of .the body sections before assembling, and in joining two sections together, the outwardly bent lugs 8' maybe slipped into place under the heads ofthe screws, and the screws then be tightened up.

The preferred formation of the slot. 11 with the rear enlarged portion 13 is of distinct advantage, in that when the securing screw 10 is tightened up, the inclined under surface of the head of the screw will exert a wedging pressure against the outer edge 14 of theenlargement 13, and thus serve to force the edge of the one body section tightly against theedge of the other.

As many of the body sections A, B, etc., may be secured together in the manner described as may be necessary to form a box structure of any desired" length, and any suitable form of closure may then be applied to the opposite ends to complete the box. For some purposes oneor both end closures may be omitted, and for other purposes the body sections, instead of being open in front, may be of annular or polygonal form, thus making up an essentially tubular structure, open at one or both ends or not, the term boxstructure being employed herein to denote .a structure formed by the described assemblage of two or more v body sections, irrespective of the particular cross-sectional contour of the said body sections. I

In the outlet-box shown in the drawings the opposite ends of the box structure are closed'by the plates 5 to form an open-front box. Each of theplates 5 is provided at one edgenvith a pair of notches 15, 15, as

' .seatsfor the opposite jaws of the lug 8', on

the outer edge of one side wall of the end body section, and an inwardly bent lug 16 between the notches 15 to fit in the enlarged portion 13 of the said slot 11, and on its opposite edgewith a longer notch 17 to receive the lug 8 on the outer edge of "the other side wall of said end body section, and adjacent to the notch 17 there is formed a depression 18 to receive the .end of the screw in said lug 8. The parts may be assembled by first slipping the lug 16 into place in the lug 8; and then seating the opposite side of the plate 5 and tightening up the securin screw.

While I have shown and described the lugs 8 and 8 as formed by' actual slitting of the metal of the body sections, it is obvious that they may in some cases be formed without slitting, as by a local bending and r, naeaoss stretching of the metal. Other variations in matters of detail may be made without departure from the invention.

I claim as my invention:

1. A metallic "box structure embodying two sections abutting edge to edge, said sections being provided at-their abutting edges with registering lugs projecting forwardly in substantially parallel planes at an angle to the plane of the" walls of said sections, and means securing said lugs together.

2. A metallic boxstructure embodying two sections abutting edge to edge, said sections being provided at their abutting edges with integral forwardly. projecting registering lugs each formed in part out of the body of its respective section, said lugs being bent in opposite directions into substantially parallel planes at an angle to the plane of the walls of said sections, and means secur ing. said lugs together.

3. A sectional box unit comprising a strip of metal having on each of two opposite edges a forwardly projecting integral lug formed in part out of the body of the strip, said lugs being bent in opposite directions into substantially parallel planes at an angle to the plane of the body of the strip.

4:. A metallic box structure embodying two sections abutting edge to edge, ascrew provided with an enlarged head having an inclined under surface, a threaded seat for the shank of the screw in one ofsaid sections, and a forwardly projecting lug on the other section having an enlarged opening adapted to receive the inclined under surface of the head of the screw, whereby the tightening of the screw serves to force the edges of the two sections together.

5. A metallic box structure embodying two sections abutting edgeto edge, a screw provided with an enlarged head having an inclined under surface carried by one section, and a forwardly projecting lug onthe abutting edge of the other section, said lug being provided with a slot' comprising an open neck portion adapted to he slipped beneath the head of the screw and an enlarged rear portionhaving a wall adjacent to said my hand.

- MARTIN M. CLAYTON. lVitnesses MARSHALL A. CHRIs'rY, FRANCIS J. TOMASSON. 

